JP2001359273A - Power supply apparatus and information processing apparatus using the power supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of conventional power supply apparatuses that drive voltage cannot be cope with by a conventional DC/DC converter circuit, when the drive voltage required by the MPU of an information processing apparatus becomes variable. SOLUTION: A reference voltage generator 202 is connected to a feedback terminal 57 of a DC-DC converter IC 201 via a 2nd resistor 56. With such a constitution, a voltage in a range which cannot be coped with by a conventional DC-DC converter can be outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power supply device and an information processing device, and more particularly to a power supply device for generating a predetermined power supply voltage and an information processing device having the power supply device.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable spread of information processing apparatuses regardless of the field. In particular, portable information processing apparatuses such as portable computers and portable information terminals have been used in a wide range of fields as their capabilities have been improved. A battery is often used as a power supply for such an information processing apparatus, and at present, when the opportunity to use the information processing apparatus has increased, it is difficult for users to reduce the power consumption of the information processing apparatus and lengthen the driving time. Is desired. For this reason, an MPU (microprocessor unit), which is one of the semiconductor devices constituting the information processing apparatus, is used.
The operation power supply voltage of t) is lowered.

On the other hand, as the manufacturing technology of semiconductor devices has improved, the structure of semiconductor devices represented by MPU has been miniaturized. In semiconductor devices that have been subjected to microfabrication,
In order to prevent dielectric breakdown, the voltage of the operation power supply is reduced.
As described above, the operating power supply voltage of a semiconductor device such as an MPU in an information processing device tends to be low.

In recent years, in consideration of power saving, a technology for dynamically changing the operating frequency of the MPU and the operating voltage of the MPU has been developed. In an information processing apparatus using such an MPU, consideration must be given to the control of the power supply voltage supplied to the MPU.

[0005] The configuration of a conventional power supply device will be described below with reference to the drawings. FIG. 6 is a circuit diagram showing a configuration of a conventional power supply device. Reference numeral 601 denotes a power input unit for inputting power for conversion for output. Reference numeral 602 denotes a power output unit, which is a DC / DC converter IC 603 described later.
And outputs the converted power. 603 is DC / DC
It is a converter IC that performs conversion control of the power output to the power output unit 602 based on the power input from the power input unit 601.

[0006] Reference numeral 600 denotes an MPU, which is a component for executing processing of an information processing apparatus equipped with the power supply device. This M
The PU 600 also sets, for the DC / DC converter IC 603, what value the power supply voltage output by the power supply device has. This setting is MPU600
Is a 5-bit D / A code (digital analog code)
Is set in the DC / DC converter IC 603. The set setting is reflected on the value of the reference voltage in the DC / DC converter IC 603. The range of voltages that can be set by the MPU 600 in this manner is called an adjustment range.

A DC / DC converter IC 603, a capacitor 604, a coil 605, an FET 606, and a diode 607 form a converter circuit. Capacitor 60
4 and the coil 605 serve as a filter. FET
A DC / DC converter IC 603 controls the switching of the FET 606, so that the power supply voltage output from the power output unit 602 can be adjusted.

Reference numeral 608 denotes a DC / DC converter IC 603
The feedback terminal is for feeding back the voltage after the conversion by the converter circuit to the DC / DC converter IC 603. The DC / DC converter IC 603 receives this feedback and determines whether or not voltage conversion is being performed appropriately. This determination is made by comparing the fed back value with the value of the reference voltage set by the MPU 600 described above. When there is a large fluctuation between the value of the fed-back voltage and the value of the reference voltage, the DC / DC converter IC 603 controls the switching of the FET 606, so that the voltage can be appropriately converted.

In such a configuration, the DC / DC converter monitors the voltage fed back to its feedback terminal, and controls the operation of the switch, so that
The output voltage within the adjustment range that can be set by the PU 600 can be varied. However, the voltage beyond the adjustment range cannot be set in the DC / DC converter IC 603 beyond the range, and this power supply device cannot cope. In particular, DC / D for which this adjustment range is narrow
In the C converter, when the drive voltage of the MPU changes dynamically, there is a possibility that the C converter cannot correspond to the voltage required by the MPU. Even when the adjustment range is wide, the accuracy often drops near the upper and lower limits of the range. When the accuracy of the voltage control is reduced, it becomes difficult to drive a semiconductor device having a strict condition regarding the accuracy of the operating voltage such as an MPU.

[0010]

The prior art described above is
The output voltage cannot be varied outside the adjustment range set by a DA converter or the like. In this case, if the adjustment range is narrow, if the power supply voltage required by the MPU dynamically changes and goes out of the adjustment range, the output range of the DC / DC converter will be exceeded. The converter has a problem that power cannot be supplied to the target MPU.

Accordingly, the present invention has been made to solve the above-mentioned problem, and a voltage device and a voltage device capable of stably supplying power to an MPU whose required power voltage dynamically changes. An object of the present invention is to provide an information processing device having the device.

[0012]

According to the present invention, there is provided a DC / DC converter having a power input section and a feedback terminal, receiving an input from the power input section and converting the input.
A power output unit for outputting a power converted by the DC / DC converter, a voltage generator for supplying a predetermined voltage, and a resistor for connecting the power output unit and the voltage generator; Wherein the terminal on the voltage generator side and the feedback terminal are connected.

According to such a configuration, stable power supply is possible even when the required power supply voltage changes dynamically.

The present invention has a digital / analog conversion circuit, a feedback terminal for feeding back an output voltage, and an output terminal. The output terminal includes an internal reference output from the conversion circuit and a voltage fed back from the feedback terminal. A DC / DC converter for sending a predetermined control signal to the output terminal according to a voltage difference, and a switch means that is turned on / off by a control signal sent from the output terminal of the DC / DC converter;
A voltage generator for generating a predetermined voltage, wherein an output of the voltage generator is connected to the feedback terminal.

According to such a configuration, stable power supply is possible even when the required power supply voltage changes dynamically.

The present invention also provides a DC / DC converter having a power supply input section and a feedback terminal, receiving an input from the power supply input section and converting the same.
A power output unit for outputting power converted by the DC converter; a constant current source device; and a resistor connecting the power output unit and the constant current source device. The constant current source device side of the resistor. A terminal and the feedback terminal are connected.

According to such a configuration, stable power supply is possible even when the required power supply voltage changes dynamically.

Further, the present invention provides a DC / DC converter having a power input section and a feedback terminal, receiving and converting an input from the power input section, and a DC / D converter.
A power supply output unit for outputting a power supply converted by the C converter; and a potential difference generating unit for generating a potential difference between the feedback terminal and the power supply output unit. A difference between the feedback voltage and the feedback voltage is generated.

According to such a configuration, stable power supply is possible even when the required power supply voltage changes dynamically.

Also, the present invention provides a DC / DC converter having a power input unit and a feedback terminal, receiving and converting an input from the power input unit, and a DC / D converter.
A power output unit that outputs power converted by the C converter, a voltage generator that supplies a predetermined voltage, a resistor that connects the power output unit and the voltage generator, and a voltage that is output from the power output unit A power supply device comprising an output voltage setting means for setting the voltage generator side terminal of the resistor and the feedback terminal;
And transmission means for transmitting the setting from the MPU to the output setting means of the power supply device, and operates by controlling an output voltage according to the setting from the MPU.

According to such a configuration, stable power supply can be performed even to the MPU whose power supply voltage changes dynamically.

The present invention also provides a DC / DC converter having a power input section and a feedback terminal, receiving and converting an input from the power input section, and a DC / D converter.
A power output unit for outputting power converted by the C converter, a constant current source device, a resistor connecting the power output unit and the constant current source device, and an output for setting a voltage output from the power output unit A power supply device comprising voltage setting means, wherein the constant current source device side terminal of the resistor is connected to the feedback terminal; an MPU; and a transmission means for transmitting settings from the MPU to output setting means of the power supply device. And operates by controlling the output voltage according to the setting from the MPU.

According to such a configuration, stable power supply can be performed even to the MPU whose power supply voltage changes dynamically.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

First, the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of an information processing apparatus according to an embodiment of the present invention.
An MPU 1 controls the information processing apparatus and performs information processing. Further, the MPU 1 makes settings for a power supply device 8 described later. 2 is an MPU-PCI bridge,
A bridge device that connects the MPU 1 to the PCI bus and the memory 3. Reference numeral 3 denotes a memory, which is a storage device for expanding programs and data executed by the information processing apparatus. Reference numeral 4 denotes a PCI-ISA bridge, which is a bridge device for connecting the PCI bus and the ISA bus. 5 is HD
D (hard disk drive), which is a non-volatile storage device that stores software used by the information processing apparatus.

Reference numeral 6 denotes an EC (embedded controller) which executes an interface between the power supply controller and the system. 7 is BIOS (Basic I / O)
System), which stores a program for controlling the operation of the information processing apparatus at the time of startup and a basic input / output program.

Reference numeral 8 denotes a power supply device which converts power from an AC power supply or a battery (not shown) into a drive power supply suitable for the information processing apparatus and supplies it (power supply wiring is not shown). As described later with reference to FIG. 2, the power supply device 8 includes a DC / DC converter IC 103 and a reference voltage generator 109. Reference numeral 9 denotes a power supply controller, which exchanges information with the EC 6 and controls the power supply device 8. Here, the exchange of information between the EC 6 and the power supply controller 9 is performed using the I2C bus. Here, the power supply controller 9 monitors the temperature of the power supply device and the like, and can perform fine power control.

Referring to FIG. 2, the power supply device 8 of the present invention will be described as follows. Reference numeral 601 denotes a power input unit for inputting power for conversion for output. Reference numeral 602 denotes a power output unit, which is a DC / DC converter IC described later.
The power source converted by 103 is output. 103 is DC
A DC / DC converter IC that controls the conversion of the power output to the power output unit 102 based on the power input from the power input unit 601.

As described above, the MPU 1 sets to the DC / DC converter IC 103 what value is to be set for the voltage of the power supply output by the power supply device. This setting is executed by the MPU 1 setting a 5-bit D / A code (digital analog code) in the DC / DC converter IC 103. The set setting is DC
This is reflected in the value of the reference voltage in the / DC converter IC 103.

A converter circuit is formed by the DC / DC converter IC 103, the capacitor 104, the coil 105, the FET 106, and the diode 107. Capacitor 10
4 and the coil 105 serve as a filter. FET
The DC / DC converter IC 103 controls the switching of the FET 106 so that the power supply voltage output from the power supply output unit 102 can be adjusted.

Reference numeral 108 denotes a DC / DC converter IC 103
And a feedback terminal for feeding back the voltage after the conversion by the converter circuit to the DC / DC converter IC 103. The DC / DC converter IC 103 receives this feedback and determines whether the voltage conversion is being performed properly. This determination is made by comparing the fed-back value with the value of the reference voltage set by the MPU 1 described above. If there is a large fluctuation between the value of the feedback voltage and the value of the reference voltage, the DC / DC converter I
When the C103 controls the switching of the FET 106, the voltage can be appropriately converted.

A reference voltage generator 109 outputs a reference voltage for obtaining a predetermined power supply output from a reference voltage output 110.

In the present invention, the reference voltage output 110 from the above-described reference voltage generator 109 and the power supply output 102 are connected by a first resistor 111 and a second resistor 112, and the midpoint thereof is input to a feedback terminal 108. I do. Even if the voltage range required by the MPU is out of the range of the DC / DC converter 201, it can be handled. In the present embodiment, the number of resistors is set to two, and the midpoint thereof is set as the feedback terminal 108. However, it is possible to add a resistor. In particular, when the environment is different depending on the system, the value of the resistor can be finely adjusted by adding a small resistor, which is convenient. In addition, when actually operating the information processing apparatus, it is necessary to secure a voltage margin for stable operation, and it is useful to add a resistor for that purpose.

Referring to FIG. 3, the detailed operation of the present invention will be described as follows. FIG. 3 is a schematic diagram showing a part of FIG. 2 in detail and supplementing the relationship between voltages. Although the arrangement is partially changed from that of FIG. 2 so that the relationship between the voltages can be easily understood, the components having the common numbers indicate the same components as those of the corresponding devices in FIG. Note that FIG. 3 further shows the internal configuration of the DC / DC converter IC 103.

A switching control circuit, a digital-to-analog conversion circuit,
A feedback reference voltage and a comparison circuit are provided.
The setting from the MPU 1 is converted by the digital-to-analog conversion circuit. A feedback reference voltage in the DC / DC converter IC 103 generates a voltage corresponding to the converted value.

The feedback reference voltage generated by the feedback reference voltage generation circuit is compared with the value of a voltage (hereinafter, referred to as Vfb) input from the feedback terminal 108 of the DC / DC converter IC 103, and DC is determined according to the result. The control circuit in the / DC converter IC 103 controls the switching of the FET 106.

Hereinafter, for the sake of explanation, the voltage at the power supply output unit 102 will be referred to as Vout, and the voltage generated by the reference voltage generator 109 will be referred to as Vref.

In the conventional power supply device, the voltage Vfb input from the feedback terminal 108 is equal to the voltage Vout at the power supply output unit 102. In the present invention, the reference voltage generator 109, the first resistor 111, the second resistor 1
The provision of 12 makes it possible to change the relationship between the voltages. The resistance value of the first resistor is R1, and the resistance value of the second resistor is R2.

First, the first resistor 111 and the second resistor 1
12 is considered. Ic is Vref
And Vout divided by the sum of R1 and R2.
That is, Ic = (Vref−Vout) / (R1 + R
2).

In the present invention, a DC / DC converter IC 10 is provided between a first resistor 111 and a second resistor 112.
3 is connected to the feedback terminal 108 of
fb is the sum of Vout and the voltage drop generated by the current Ic in the first resistor 111. Assuming that the magnitude of the voltage drop generated in the first resistor 111 is Vc, Vc is Ic
And R1. That is, Vc = Ic × R1
It is.

When this Vc is used, Vfb becomes V
out and Vc. That is, Vfb = Vo
ut + Vc. Looking at this relationship, just Vou
t is obtained by subtracting Vc from Vfb. That is, in the present invention, the DC / DC converter IC 10
By utilizing the voltage drop of the reference voltage generator 109 and the first resistor 111 from the voltage of the third feedback terminal 108, the actual power supply output voltage can be reduced.

Actually, the DC / DC converter IC 103 handles the voltage Vfb at the feedback terminal, and the power supply output unit 102 of the power supply device can generate a stable and accurate low-voltage power supply, Vout. In a practical example, the DC / DC converter I
It is possible to further reduce by 0.15 V for the control range of C from 1.25 V to 2.00 V.

A second embodiment of the present invention will be described below with reference to the drawings. The second embodiment uses a constant current source instead of the reference voltage generator 109 in the first embodiment. FIG. 4 is a circuit diagram showing a configuration of a power supply device according to the second embodiment of the present invention. By connecting the constant current source 150 to the second resistor 112, it can be used as a substitute for the reference voltage generator 109 in the first embodiment.

According to the second embodiment, as compared with the first embodiment, the voltage generated at the second resistor is stabilized, and a more accurate and wide-range voltage output than the first embodiment can be obtained. It becomes possible. That is, in the first embodiment, the reference voltage generated by the reference voltage generator is always a constant value. For this reason, even when another value is newly set for Vout, the value of Vref remains constant, so that the current value Ic changes and the voltage drop Vc also changes. If a higher accuracy is required for a desired output voltage, it is necessary to set a feedback reference voltage of the DC / DC converter IC 103 in consideration of a change in the voltage drop Vc.

However, according to the present embodiment, since a constant current is supplied to the resistor, the value of the voltage drop does not fluctuate, which is advantageous for more precise control.

As another embodiment of the present invention, the reference voltage generator of the first embodiment can be shared with a power supply of another apparatus operating in the information processing apparatus. For example, the reference voltage generator can be shared with a power supply for an HDD. In the information processing apparatus of the present embodiment, H
The power supply voltage of the DD is 5 V, and this value is generally lower than the pre-conversion voltage (15 V) of the power supply voltage.

For example, when the voltage generated by the reference voltage generator is 5 V
In this case, when converting a voltage of 15 V to 5 V, energy is lost due to heat generated by the current. According to the configuration of the present embodiment, power conversion loss at the time of generation of the reference voltage can be reduced, and the battery drive time can be extended.

Here, in addition to the power supply for the HDD, a power supply for the CD drive or a power supply for the DVD drive can be used instead of the reference voltage generator. If access to the HDD is frequently performed and supply of power for operation of the HDD may become unstable, a power supply for a CD drive or a power supply for a DVD drive may be used as the reference voltage generator.

In each of the above embodiments, a diode 107 as shown in FIG.
It is also possible to use a synchronous rectification method in which an NMOSFET 160 is connected in parallel with the above. In the synchronous rectification method, DC / DC
Converter IC103 is NMOSFET160 and FET
There is a characteristic that high-efficiency conversion becomes possible by operating the 106 in synchronization. By performing more efficient conversion, power saving can be achieved.

These embodiments can be selectively used as appropriate according to the configuration of the information processing apparatus.

[0051]

As described above, according to the present invention, stable power supply can be achieved even when the required power supply voltage changes dynamically.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an information processing apparatus using a power supply device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a power supply device according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram showing the operation of the power supply device according to the first embodiment of the present invention.

FIG. 4 is a circuit diagram showing a configuration of a power supply device according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram showing a configuration of a power supply device according to an embodiment in which a synchronous rectification method is introduced into the first embodiment of the present invention.

FIG. 6 is a circuit diagram showing a configuration of a conventional power supply device.

[Explanation of symbols]

1 MPU, 2 MPU-PCI bridge, 3 memory, 4 PCI-ISA bridge, 5 HDD, 6 E
C, 7 BIOS, 8 power supply device, 9 power supply controller, 101 power supply input unit, 102 power supply output unit, 103
... DC / DC converter IC, 104 ... capacitor, 1
05 ... coil, 106 ... FET, 107 ... diode,
108: feedback terminal, 109: reference voltage generator, 110: reference voltage output, 111: first resistor, 11
2: second resistor, 150: constant current source, 160: NMOS
FET, 601, power input section, 602, power output section, 6
03 DC / DC converter IC, 604 capacitor, 605 coil, 606 FET, 607 diode, 608 feedback terminal

Claims (7)

[Claims] 1. A DC / DC converter having a power input unit, a feedback terminal, receiving an input from the power input unit and converting the input, and a power source for outputting a power converted by the DC / DC converter An output unit, a voltage generator that supplies a predetermined voltage, and a resistor that connects the power output unit and the voltage generator. The voltage generator side terminal of the resistor is connected to the feedback terminal. A power supply device characterized by being performed. 2. The power supply device according to claim 1, wherein said DC / DC converter includes conversion voltage setting means, and executes voltage conversion according to an external setting. 3. A digital / analog conversion circuit, comprising: a feedback terminal for feeding back an output voltage; and an output terminal. A voltage difference between an internal reference output from the conversion circuit and a voltage fed back from the feedback terminal. A DC / DC converter for transmitting a predetermined control signal to the output terminal, a switch means that is ON / OFF controlled by the control signal transmitted from the output terminal of the DC / DC converter, and a voltage for generating a predetermined voltage And a generator connected to an output of the voltage generator to the feedback terminal. 4. A DC / DC converter having a power input unit, a feedback terminal, receiving an input from the power input unit and converting the input, and a power source for outputting a power converted by the DC / DC converter An output unit, a constant current source device, and a resistor for connecting the power output unit and the constant current source device, wherein the constant current source device side terminal of the resistor and the feedback terminal are connected. A power supply device characterized by the above-mentioned. 5. A DC / DC converter having a power supply input section, a feedback terminal, receiving and converting an input from the power supply input section, and a power supply for outputting a power supply converted by the DC / DC converter. An output unit; and a potential difference generating unit that generates a potential difference between the feedback terminal and the power output unit, wherein a difference is generated between an output voltage from the power output unit and a feedback voltage to the feedback terminal. And power supply. 6. A DC / DC converter having a power input unit, a feedback terminal, receiving and converting an input from the power input unit, and a power source for outputting a power converted by the DC / DC converter An output unit, a voltage generator that supplies a predetermined voltage, a resistor that connects the power output unit and the voltage generator, and an output voltage setting unit that sets a voltage output from the power output unit; A power supply unit to which the voltage generator side terminal of the resistor and the feedback terminal are connected; an MPU; and a transmission unit for transmitting a setting from the MPU to an output setting unit of the power supply unit. An information processing apparatus that operates by controlling an output voltage in accordance with the setting of (1). 7. A DC / DC converter having a power supply input section, a feedback terminal, receiving and converting an input from the power supply input section, and a power supply for outputting a power supply converted by the DC / DC converter. An output unit, a constant current source device, a resistor connecting the power supply output unit and the constant current source device, and output voltage setting means for setting a voltage output from the power output unit. A power supply device to which a constant current source device side terminal and the feedback terminal are connected; an MPU; and a transmission unit for transmitting a setting from the MPU to an output setting unit of the power supply device. An information processing apparatus which operates by controlling an output voltage in accordance with the information.